<template>
  <div>
    <router-link
      tag="div"
      to="/"
      class="header-abs"
      v-show="showAbs">
      <div class="iconfont header-abs-back">&#xe624;</div>
    </router-link>
    <div
      class="header-fixed"
      v-show="!showAbs"
      :style="opacityStyle"
    >
      <router-link to="/">
        <div class="iconfont header-fixed-back">&#xe624;</div>
      </router-link>
      景点详情
    </div>
  </div>
</template>

<script>
export default {
  name: 'DetailHeader',
  data () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        let opacity = top / 140
        opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = { opacity }
        this.showAbs = false
      } else {
        this.showAbs = true
      }
    }
  },
  activated () {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>

<style lang="scss" scoped>
  @import "~@/styles/varibles.scss";
  .header-abs{
		position: absolute;
		left: .2rem;
		top: .2rem;
		width: .8rem;
		height: .8rem;
		line-height: .8rem;
		border-radius: .4rem;
		text-align: center;
		background: rgba(0, 0, 0, .8);
		.header-abs-back{
			color: #fff;
			font-size: .4rem;
		}
	}
  .header-fixed{
		z-index: 2;
		position: fixed;
		top: 0;
		left: 0;
		right: 0;
		height: $headerHeight;
		line-height: $headerHeight;
		text-align: center;
		color: #fff;
		background: $bgColor;
		font-size: .32rem;
		.header-fixed-back{
			position: absolute;
			top: 0;
			left: 0;
			width: .64rem;
			text-align: center;
			font-size: .4rem;
			color: #fff;
		}
	}
</style>
